Anatomy Test 2: Thoracic Muscles Insertion,origin

Front 1

Diaphragm(o,i)

Back 1

origin: crura from L1,L2(left), and L1-L3(right). Costal; medial and arcuate ligaments, inner aspect from lower 6 ribs. Sternal; two slips from posterior aspect of xiphoid

Insertion: Central tendon

Front 2

Diaphragm(f,n)

Back 2

Function: Inspiration and assists in lowering intra-abdominal pressure

Nerve: (motor) Phrenic nerve(C3,4,5)
(sensory) phrenic, intercostals (6-12) and upper two lumbar nerve roots

Front 3

External intercostals(o,i)

Back 3

Origin:inferior border of ribs

Insertion: superior border of ribs, passing down and backwards

Front 4

External intercostals(f,n)

Back 4

Function: Immobilize intercostal spaces during respiration. Aids in forced inspiration by elevating ribs.

Nerve: Muscular collateral branches of intercostal nerves(anterior rami)

Front 5

Innermost intercostals(o,i)

Back 5

Origin: Internal aspect of the ribs above and below

Insertion:Internal aspect of the rib above and below

Front 6

Innermost intercostals(f,n)

Back 6

Function: fix intercostal spaces during respiration

Nerve: Muscular collateral branches of intercostal nerves

Front 7

Internal intercostals(o,i)

Back 7

Origin: Inferior border of the ribs, as far back as the posterior angles

Insertion: Superior borders of the ribs. Pass obliquely down and backwards

Front 8

Internal intercostals(f,n)

Back 8

Function: Fix intercostal spaces during respiration. Aids in forced inspiration by elevating the ribs.

Nerve:Muscular collateral branches of intercostal nerves(anterior rami)

Front 9

Levatores Costarum(o,i)

Back 9

Origin: Transverse processes C7-T11

Insertion: Posterior surface and angle of rib below

Front 10

Levatores Costarum(f,n)

Back 10

Function: Elevates ribs

Nerve: Primary posterior rami

Front 11

Pectoralis Major(o,i)

Back 11

Origin: Clavicular head, medial half of clavicle. Sternocostal head-lateral manubrium and sternum, six upper costal cartilages and external oblique aponeurosis.

Insertion: Lateral lip of bicipetal groove of humerus and anterior lip of deltoid tuberosity

Front 12

Pectoralis Major(f,n)

Back 12

Function: Clavicular head;flexes and adducts arm. Sternal head; adducts and medially rotates arm. Accessory for inspiration.

Nerve: Medial and lateral pectoral cord(C6,7,8)

Front 13

Pectoralis Minor(o,i)

Back 13

Origin: Ribs 3,4, and 5.

Insertion: Medial and upper surface of coracoid process of scapula

Front 14

Pectoralis Minor(f,n)

Back 14

Function: If scapula is fixed they elevate the ribs. Also protracts scapula and assists serratus anterior.

Nerve: Medial pectoral nerve(C8, T1)

Front 15

Serratus anterior(o,i)

Back 15

Origin: Upper eight ribs and anterior intercostal membranes from midclavicular line. Lower four interdigitating with external oblique

Insertion: Inner medial border scapula. 1 and 2: upper angle; 3 and 4: length of costal surface ; 5-8: inferior angle

Front 16

Serratus anterior(f,n)

Back 16

Function: laterally rotates and protracts scapula

Action:Long thoracic nerve (C5, 6, 7) (from roots) slips from ribs 1 and 2: C5; 3 and 4: C6; 5-8: C7)

Front 17

Serratus Posterior Inferior(o,i)

Back 17

Origin:Spinous processes and supraspinous ligaments of T11-L2

Insertion:Posterior aspect of ribs 9-12

Front 18

Serratus Posterior Inferior(f,n)

Back 18

Function: assists in forced expiration

Nerve:Anterior rami(T9-12)

Front 19

Serratus Posterior Superior(o,i)

Back 19

Origin:Spinous processes and supraspinous ligaments of C7-T2

Insertion: Posterior aspect of ribs 2-5

Front 20

Serratus Posterior Superior(f,n)

Back 20

Function: Assists in forced inspiration

Nerve: Anterior primary rami (T2-5)

Front 21

Subcostalis(o,i)

Back 21

Origin:Internal posterior aspects of lower six ribs

Insertion:Internal aspects of ribs two to three levels below

Front 22

Subcostalis(f,n)

Back 22

Function: Depresses lower ribs

Nerve: Muscular collateral branches of intercostal nerves

Front 23

Transversis Thoracis(o,i)

Back 23

Origin: Lower third of inner aspect of sternum and lower three costosternal junctions

Insertion: Second to sixth costal cartilages

Front 24

Tranvsversis Thoracis(f,n)

Back 24

Function:Depresses upper ribs

Nerve: Muscular collateral branches of intercostal nerves